These robots race without using Extreme Gear, instead curling up into a wheel configuration and blazing forwards under their own power. In cutscenes they are shown with the ability to fly.

Story

In Zero Gravity, Dr. Robotnik has established the Meteor Tech robotics corporation as a front for his activities in the high-technology region of Monopole. Described as "the leading security company" in the game's opening sequence, Meteor Tech produces SCR-HD and SCR-GP model 'bots in its MeteorTech Sparkworks, and controls them from Crimson Tower via the Mother Computer. It seems to have been Robotnik's plan to sell his (apparently harmless) robots to various other organizations around Monopole, saturating the economy with Meteor Tech models, and then later seize control of the region in one fell swoop by setting the machines to rampage.

Eggman's plan is derailed before the game begins, not by Sonic, but by beings long dead. Somewhat unwisely, Eggman used an ill-understood piece of ancient Babylonian technology - discovered in Crimson Crater - as the core of his Mother Computer. When an Ark of the Cosmos crashes as a meteorite outside Crimson Tower, the SCR robots go berserk, compelled by the malfunctioning mainframe to gather all 5 Arks and bring them to Babylon Garden.

Trivia

It can often be difficult to distinguish between SCR-GP and SCR-HD. During gameplay, HD's icon is gold while GP's is silver, and GP's character model is tinted brown. Their "eyes" are also different; GP's are rectangular with a red light while HD's form a blue chevron.